Speed governor



Gd. 8, 1946. RUBY 2,409,070

SPEED GOVERNOR Filed April 27, 1945 Patented Oct. 8, 1946 SPEED GOVERNOR Thomas M. Ruby, Whitmore Lake, Mich, assignor to King-Seeley Corporation, Ann Arbor,'Mich., a corporation of Michigan Application April 27, 1945, Serial No. 590,541

8 Claims. 1

This invention relates to speed governors for internal combustion engines, and more particularly, to governors of the "velocity or "mixtureflow type, consisting essentially of a valve or throttle-plate mounted on a shaft extending transversely of the intake manifold of an engine to be governed; the axis of said shaft lying to one side of the center line of the manifold passage, whereby the forces exerted on the throttleplate by the passage of fuel mixture through the manifold tend to move the plate toward closed position, said forces varying in value as the plate changes position. The reactance device in the form of a spring or combination of springs, connected to the throttle-plate shaft through a suitable linkage, serves to balance the closing forces exerted upon the throttle-plate, in all positions, at governed speed; the position of the throttleplate, and, hence, the amount of fuel mixture passing to the engine, being dependent upon the load imposed upon the engine at any given moment In velocity-type governors, the forces acting upon the throttle-plate due to the passage of fuel mixture through the intake conduit have been considered two-fold, that is, impingement of the fuel mixture upon the respective areas of the throttle-plate lying upon opposite sides of the off-center shaft, and the difference in fluid pressure upstream and downstream of the throttleplate. As is well known, the fluid pressure upstream of the throttle-plate is substantially that of the atmosphere when the carburetor throttlevalve is in open position, as is the case when the engine is being operated under control of the governor. The pressure downstream of the governor valve at governed speed, varies with the load from a value in the neighborhood of 2 inches of Hg at full load to perhaps 20 inches of Hg at no load.

It has been recognized that the governed speed of an engine controlled by a velocity-type governor changes with variations in the altitude at which the engine is operated, both the full-load and no-load speeds of the engine increasing as the altitude increases, and the atmospheric pressure decreases. In the past, this phenomenon has not been considered important. particularly as regards the increase of full-load speed, since such increase has been considered an advantage, in that it automatically compensated. to a certain degree, for the loss of engine power incident to the reduction in air density and atmospheric pressure at elevated altitudes. Under presentday conditions, in which engine speeds have become higher, whereby manifold pressures and resultant fuel velocities change but slightly with variations in speed, it has been found that the reduction in atmospheric pressure and density at elevated altitudes operates to reduce the forces acting upon the governor valve to such an extent as to substantially reduce the ClOSiIlg effort on the valve, thus increasing the no-load speed to a harmful extent; thus, an engine equipped with a velocity-type governor set for a no-load speed at sea level of 3,000 R. P. M. to 3,200 R. P. M. will, at high altitudes, attain a no-load speed of 4,000 to 4,500 B. P. M., or, in other words, a speed of the order of 30% greater than that at which the engine was designed to operate. By means of the present invention, this tendency may be controlled so that the no-load speed of an engine governed in accordance with the invention may be maintained substantially constant regardless of the altitude at which it is operated. However, since an increase in the full-load speed at high altitudes has certain advantages, it is desirable that the correction shall be confined to the no-load end of the load-speed curve, which is accomplished according to the present invention.

The general object of the present invention is the provision of a velocity-type governor including means operable upon a predetermined decrease in atmospheric pressure for supplementing the forces normally urging the governor valve toward closed position.

A further object is the provision of a governor including means operable upon a predetermined decrease in atmospheric pressure for supplementing the forces normally urging the governor toward closed position, such supplementary forces being applied only under no-load and light-load conditions.

A further object is the provision, in a governor as described, of means cooperating with the conventional anti-steal piston for supplementing, at high altitudes or under conditions of reduced atmospheric pressure, the forces normally urging I the throttle valve toward closed position.

Other and further objects, features and advantages will be apparent from the description which follows, taken in connection with the accompanying drawing. in which- Fig. 1 is a sectional view of a governor according to the present invention, taken on a plane including the axis of the fuel-mixture conduit and normal to the axis of the throttle-valve shaft; and

.Fig. 2 is a side elevation of the governor, with spring-box cover removed, illustrating the reactance device for balancing the forces exerted upon the governor-plate by the passage of fuel.

In order to facilitate an understanding of the invention, reference is made to the embodiment thereof shown in the accompanying drawing, and detailed descriptive language is employed. It will, nevertheless, be understood that no limitation is thereby intended, and that various changes and alterations are contemplated such as would ordinarily occur to one skilled in the art to which the invention relates.

Referring to the drawing, the numeral It] designates a governor body, which may suitably take the form of a casting, adapted to be inserted in the fuel-intake manifold of an internal combustion engine, between the carburetor andthecylinders. The governor body includes a fuel-mixture conduit II, which is preferably cylindrical in" form, though not necessarily so. A throttleplate I2 is secured upon the shaftor spindle I3, which is journaled transversely of the fuel -niixture conduit and to one side of the center line thereof, so that the upstream side I4 of the throttle-plate has a substantially greater area than has the downstream side I5- of the plate; The flow of fuel mixture is in the direction of the arrows in Fig. l.

B virtue of the unbalanced nature of the throttle-plate i2, the tendency of the plate is to move toward closed position (clockwise in Fig. 1) under the forces exerted by the passage of fuel mixture through the conduit Ii. may be balanced, at governed speed, in all llOttle-po-sitions, by a properly designed reactance device, such as that illustrated in Fig. 2, wherein a spring I5, adjustably secured at one end, has its other end connected by means of a ribbon I l with a cam I8 secured on a portion of the throttleshaft I3 extending outside of the governor body It. The details of the reactance mechanism form no part of the present invention and will not be further described; a

It is customary to provide, in conjunction with velocity-type governors; a device known as an anti-steal or anti-cheat piston, the nature and function of which are Well known in the art. In the present instance, the anti-steal piston is employed to perform an additional function, namely, that of supplementing, at high altitudesor under conditions of decreased atmospheric pressure, the forces normally acting to move to urge the throttle-plate toward closed position. Thus, referring to Fig. 1, the governor body I E! is formed to provide; at one side, a cylinder i3, which is vented to'the atmosphere at 29. A piston 2|, slidable in the cylinder !9, is connected to-the throttle-plate I2 through a piston-rod 22, which engages the arm 23 secured upon the upstream face of the throttle-plate.

The body I6 is provided with a longitudinal bore 24, communicating at its lower endwith a series of transverse passages or ports 25, 26, 21, 28,opening into the fuel-mixture conduit II at points adjacent the downstream edge of the throttle-plate when the latter is in approximately-half-load position; A groove 29 formed in the piston-rod 22 provides communication between the passage 24 and the cylinder I9.

A second cylinder 30 formed in the governor body communicates with the passage 24' by means of a passage 3| and communicates with the fuel-mixture conduit II, at a point upstream of the throttle-plate, through a passage 32 and a series of spaced ports -33, 34; 35. The cylinder 30 This tendency contains a piston 31, which is adapted, by movement toward the right in Fig. 1, progressively to close off the port 3335, the piston 31 being connected by means of a link 38 with an expansible sealed cartridge 39 containing a gas at sea-level atmospheric pressure. The piston 31 is balanced to pressures by cylinder tubeingvented in both ends: The cylinder 30- which contains the cartridge 39, and the piston 31 is vented to atmosphere at 4| and 42.

The construction thus described operates in the following manner: When the carburetor or manually-controlled throttle-valve is substantially closed; the. pressure throughout the entire length of the, fuel-mixture conduit II corresponds to the engine vacuum, and the inner end of the cylinder I9' is, therefora'subject to the engine vacuum through the ports 25-28, the passage 24 and groove 29. Since the outer end of the cylinder I9 is open to the atmosphere, there is an inwardlyacting force upon the piston 2|, which urges the throttle-plate :2 toward closed position. This is.

the normal anti-cheat function of the piston 2|: and requires no further explanation.

In order to supplement the forces normally act'- ing to close the throttle-plate, when the engine is operating at elevated altitudes, with carburetor throttle-valve open, engine vacuum is introduced into the inner end of the cylinder I9 through the ports 2528, passage 24 and groove 29, thus causing an inwardly-acting force upon the piston 2i. Since this additional force is not desired between half load and full load, the ports 25-28 are disposed in such a position that when the throttleplate I2 is in fairly wide-open position the ports will be on the upstream side of the lower edge of the throttle-plate, and thus will be exposed to substantially atmospheric pressure. However, as the load decreases, and the throttle-plate moves toward closed position, the ports 25-28 are progressively transferred to the high-vacuum side of the throttle-plate, thereby progressively subjecting the inner end of the cylinder I9 to the engine vacuum, and thus progressively increasing the total of the closing forces acting upon the throttleplate.

Since this additive force is desirable only at elevated altitudes, the piston 3'! is employed for controlling its application in the following manner: Normally, i. e., at low altitudes, atmospheric pressure is introduced to the cylinder I9. through the passage 32, ports 3336', passages 3| and 24, and groove 29, thus dissipating the vacuum introduced through the port 25-428; However, as the altitude increases and the atmospheric pressure decreases, the cartridge 39 will expand and the piston 31 will progressively seal offthe ports 3336, thus progressively diminishing the extent to which the atmosphere is introduced into the cylinder I9. At a certain predetermined altitude, at which the atmospheric pressure has diminished to a predetermined value, all of the ports 33-36 will have been closed and a maximum closing force may be exerted upon the piston, 2| by engine vacuumintroduced through the ports 25-28. 33-36 are progressively uncovered; and the vacuum in the cylinder I9 is thus progressively dissipated or lessened in value.

From the foregoing description it'will be apparent that the present invention providesmeans for accomplishing the various objects hereinbefore stated.

Having now described: my invention, what: I.

As the altitude decreases, the ports claim as new, and desire to secure by Letters Patent, is:

1. In a speed governor for internal combustion engines, a governor body enclosing a fuel-mixture conduit, an unbalanced throttle-plate supported in said conduit and adapted to be moved toward closed position by the flow of fuel mixture tnerethrough, means including a pressure-responsive element for urging said throttle-plate toward closed position, and means for progressively subjecting said pressure-responsiv element to in creasing degrees of engine vacuum said throttle-plate approaches its closed position.

2. In a speed governor for internal combustion engines, a governor body enclosing a fuel-mixture conduit, an unbalanced throttle-plate supported in said conduit and adapted to be moved toward closed position by the flow of fuel mixture therethrough, means including a pressure-responsive element for urging said throttle-plate toward closed position and means for progressively subjecting said pressure-responsive element to in creasing degrees of engine vacuum as said throttle-plate approaches its closed position; said last means comprising a series of ports spaced longitudinally of said fuel conduit on the downstream side of said throttle-plate, and conduit means connecting said ports and said pressureresponsive element.

3. In a speed governor for internal combustion engines, a governor body enclosing a fuel-mixture conduit, an unbalanced throttle-plate supported in said conduit and adapted to be moved toward closed position by the flow of fuel mixture therethrough, means including a pressure-responsive element for urging said throttle-plate toward closed position, means for progressively subjecting said pressure-responsive element to increasing degrees of engine vacuum as said throttle-plate v approaches its closed position, and means counteracting said last means when the barometric pressure of the surrounding atmosphere is not substantially less than normal sea-level barometric pressure.

4. In a speed governor for internal combustion engines ,a governor body enclosing a fuel-mixture conduit, an unbalanced throttle-plate supported in said conduit and adapted to be moved toward closed position by the flow of fuel mixture therethrough, means including a pressure-responsive element for urging said throttle-plate toward closed position, means for progressively subjecting said pressure-responsive element to increas ing degrees of engine vacuum as said throttleplate approaches its closed position, and means for progressively counteracting said last means as the barometric pressure of the surrounding atmosphere approaches normal sea-level barometric pressure.

5. In a speed governor for internal combustion engines, a governor body enclosing a fuel-mixture conduit, an unbalanced throttle-plate supported in said conduit and adapted to be moved toward closed position by the flow of fuel mixture therethrough, means including a pressure-responsive element for urging said throttle-plate toward closed position, means for progressively subjecting said pressure-responsive element to increasing degrees of engine vacuum as said throttleplate approaches its closed position, and means for subjecting said element to atmospheric pressure when the barometric pressure of the surrounding atmosphere is not substantially less than normal sea-level atmospheric pressure.

6. In a speed governor for internal combustion engines, a governor body enclosing a fuel-mixture conduit, an unbalanced throttle-plate supported in said conduit and adapted to be moved toward closed position by the flow of fuel mixture therethrough, means including a pressure-responsive element for urging said throttle-plate toward closed position, means for progressively subjecting said pressure-responsive element to increasing degrees of engine vacuum as said throttle-plate approaches its closed position, and means for progressively subjecting said element to atmospheri pressure as the barometric pressure of the surrounding atmosphere approaches normal sea-level atmospheric pressure.

'7. In a speed governor for internal combustion engines, a governor body enclosing a fuel-mixture conduit, an unbalanced throttle-plate supported in said conduit and adapted to be moved toward closed position by the flow of fuel mixture therethrough, means including a pressure-responsive element for urging said throttle-plate toward closed position, means for progressively subjecting said pressure-responsive element to increasing degrees of engine vacuum as said throttleplate approaches its closed position, and means for subjecting said element to atmospheric pressure when the barometric pressure of the surrounding atmosphere is not substantially less than normal sea-level atmospheric pressure, said last means comprising a chamber formed in said governor body; means affording communication between said chamber and said element, means affording communication between said chamber and the atmosphere, and means responsive to changes in barometric pressure for interrupting said communication between said chamber and said element when the barometric pressure falls and for re-establishing said communication when said pressure rises,

8. In a speed governor for internal combustion engines, a governor body enclosing a fuel-mixture conduit, an unbalanced throttle-plate supported in said conduit and adapted to be moved toward closed position by the flow of fuel mixture therethrough, means including a pressure-responsive element for urging said throttle-plate toward closed position, means for progressively subjecting said pressure-responsive element to increasing degrees of engine vacuum as said throttle-plate approaches its closed position, and means for progressively subjecting said element to atmospheric pressure as the barometric pressure of the surrounding atmosphere approaches normal sealevel atmospheric pressure, said last means comprising a chamber formed in said governor body; means afiording communication between said chamber and said element, a series of ports opening into said chamber, means affording communication between said ports and the atmosphere, a member movable in said chamber for progressively closing said ports, and means responsive to barometric pressure for actuating said last member progressively to close said ports as the barometric pressure falls and progressively to open them as said pressure rises.

THOMAS M. RUBY. 

